1. Field of the Invention
This invention relates to a vehicular charging generator having a one-way clutch.
2. Discussion of the Invention
FIG. 5 and FIG. 6 show a conventional vehicular charging generator (hereinafter, generator) which is shown, for instance, in Japanese Unexamined Patent Publication No. 101353/1981, wherein FIG. 5 is a construction view of a generator and FIG. 6 is a partially magnified view showing the detailed construction of a one-way clutch. In FIGS. 5 and 6, numeral 1 designates a main body of a generator which is constructed as follows. Numeral 2 designates a front bracket, numeral 3 designates a rear bracket, and the central portions of the brackets are installed with a front bearing 4 and a rear bearing 5, respectively. Numeral 6 designates an armature having an armature core 6a and an armature coil 6b which is wound around the armature core 6a. The armature core 6a is interposed between the both brackets by clamping it to the both brackets by a clamp bolt 7 in the horizontal direction of FIG. 5.
Numeral 8 designates a rotor having a rotor shaft 8a, a male screw 8b which is worked on the right end portion of the rotor shaft 8a in FIG. 5, a cylindrical pole body 8c having claw-formed magnetic poles which are fitted to the rotor 8a, a field coil 8d which is wound around the pole body 8c, and slip rings 8e which are attached to the rotor shaft and connected to the field coil 8d. Further, the rotor 8a is rotatably supported by the both brackets 2 and 3 through the bearings 4 and 5 such that the pole body 8c is disposed on the inner side of the armature core 6a.
Numeral 9 designates brushes which supply an exciting current to the field coil 8d through the slip rings 8e. Numeral 10 designates a rectifier which rectifies an alternate current power generated in the armature coil 6b. The brushes 9 and the rectifier 10 are attached to the inside of the rear bracket 3. Numeral 11 designates a fan which is disposed outside of the front bracket 2 and is fitted to the rotor 8a and which rotates along with the rotor 8 and sends outer air to the inside of the main body of the generator to thereby cool it. The main body of the generator 1 is constructed as above.
Numeral 12 designates a one-way clutch, numeral 13 designates a pulley and the one-way clutch 12 is arranged between the rotor shaft 8a and the pulley 13.
Next, an explanation will be given of the detailed construction of the one-way clutch 12 also in reference to FIG. 6. Numeral 21 designates a clutch inner, numeral 22 designates a clutch outer, and notation 22a designates a plurality of wedge-like grooves (FIG. 6). The plurality of grooves 22a are provided at the inner peripheral portion of the clutch outer 22 in the circumferential direction, and as shown in FIG. 6, each has a wedge-shaped section in a direction orthogonal to the shaft in which the depth thereof in the radial direction becomes shallower toward the lefthand direction. Numeral 23 designates rollers, and numeral 24 designates roller springs. The rollers 23 are inserted in the grooves 22a between the clutch inner 21 and the clutch outer 22, and are pressed by the roller springs 24 in a direction counter to an arrow mark R in FIG. 6 in which the rotors 8 are driven.
The clutch inner 21 is fitted to the rotor shaft 8a and is prevented from coming out in the axial direction by a nut 25 (FIG. 5) which is engaged with the male screw 8b. The clutch outer 22 is press-fitted to the pulley 13.
Next, an explanation will be given of the operation.
This generator is a three-phase synchronous generator wherein the rotor 8 is driven in the arrow mark R direction of FIG. 6 through a belt (not shown) which spans between an engine, not shown, that is a power unit and the pulley 13. By the rotation of the rotor 8, a three-phase alternate current power is generated in the armature winding 6b, and a power necessary for a vehicle is supplied by converting the alternate current power to a direct current by the rectifier 10.
The one-way clutch 12 operates as follows in pulsating or accelerating or decelerating of an engine. That is, when the engine is accelerated, the clutch transmits a torque and the rotor is driven by the engine. Conversely, when the engine is decelerated, the rotor is not decelerated since the clutch slips, and continues running by inertia thereby achieving effects of the promotion of energy efficiency, the promotion of belt life and the like.
A further detailed explanation will be given of the operation of the one-way clutch 12. The pulley 13 is driven in the arrow mark R direction of FIG. 6 by the engine. When the rotation speed of the engine is faster than the rotation speed of the rotor 8 of the generator, the rollers 23 which are being pushed in a direction counter to the arrow mark R by the roller springs 24, move at the inside of the groove 22a in the lefthand direction of FIG. 6. As a result, the rollers 23 wedge in between the clutch inner 21 and the clutch outer 22, thereby transmitting the power of the pulley 13 to the rotor shaft 8a.
On the other hand, in decelerating the engine, especially in rapidly decelerating it, the rotation speed of the clutch inner 21 becomes faster than the rotation speed of the clutch outer 22 by the inertia force of the rotor 8. Accordingly, the wedging of the rollers 23 is released since the rollers 23 move in the righthand direction of FIG. 6 against the spring force of the roller springs 24. Therefore, the rotor 8 is decelerated while converting the rotational energy of the rotor, per se into an electric power, without being decelerated by the deceleration of the engine.
There are following problems since the conventional generator is constructed as above.
(1) The clutch outer 22 and the pulley 13 are separately constructed, and the pulley 13 is press-fitted to the clutch outer 22, and therefore, the number of parts is increased and much time is required for the integrating operation. Further, the quality may dispersingly deteriorated by the lowering of accuracy at the engaging portions of the rollers due to a warp of the clutch outer which has been accompanied by the press-fitting operation. PA1 (2) After the clutch inner 21 has been fitted to the rotor shaft 8a, it is prevented from coming out by the nut 25, and therefore, the number of parts is similarly increased and much time is required for the integrating operation. PA1 (3) There is no independent bearing between the clutch outer 22 and the clutch inner 21. Therefore, no consideration has been given to a load of the clutch which is applied by driving the belt, and the like and the improvement of durability has been requested. PA1 (4) No consideration has been given to the dust proof and water proof performance of the clutch. Therefore, a measure in view thereof is necessary.